Carton end closure



Sept. 24, 1963 E. P. ADAMS 3,104,795

CARTON END CLOSURE Filed June 2, 1961 2 Sheets-Sheet 2 INVENTOR. fiA iif 2 4mm:

United States Patent '0 3,104,795 CARTGN END CLOSURE Ernest P. Adams, Atherton, Calif assign'or to Crown Zellerbach Corporation, San Francisco, Calif a corporation of California Filed June 2, 1961, Ser. No. 114,358 2 Claims. (Cl. 229-39) This invention relates generally to containers and more particularly to carton type containers particularly adapted for packaging products such as particulate or semisolid frozen foods and like edibles. Still more particularly this invention relates to an end-loading paperboard carton which has a novel end closure provided at at least one of its opposite ends, and preferably at both of its opposite ends.

While the subject carton may be advantageously employed for use in the packaging of food products to: be frozen, it also has utility in the packaging of numerous other products. However, by way of example, hereinafter reference will bedirected to the cartons use as a frozen food carton which is generally intended to be overwrapped with a wax paper or plastic wrapper on which is applied descriptive material about the product packaged and the producer thereof. Preferably the subject carton is made from flexible yet sturdy paperboard commonly employed for cartons of this nature, such paperboard preferably being treated with wax or a suitable plastic, such as polyethylene, to increase the moisture barrier characteristics thereof.

In the carton art, it is a well known fact that any savings of paperboard material, however slight, in any given carton is a very import-ant fatcor in that cartons of the general type discussed herein are produced, sold and used in very large quantities. As a result, saving of material in one carton of a given type results in substantial savings when such individual carton saving is multiplied by the large number of such type cantons frequently purchased by a carton user, such as a frozen food producer. It is also 'well known that cartons of the discussed types must be adapted for erecting, filling and closing on high speed automatic machinery, so that the labor costs attendant to carton filling and closing may be minimized and so that large numbers of cartons may be filled and closed in short periods of time.

An important feature of the subject carton resides in the particular construction of the end closure means there of, which particularly adapts the carton to be closed on automatic machinery without interference between the flap means employed to close one and preferably both carton ends. Also, the subject carton employs a minimum amount of paperboard in its end closures so that a saving of material is effected and so that carton unit cost is minimized.

Accordingly, objects of the present invention include the provision of a carton which has novel closure means at one and preferably both ends thereof; the provision of a carton end closure defined by a series of cooperable yet non-interferring closure flaps; the provision of shoulder means on at least one closure flap effective to preclude interference between such flap and an opposite flap during carton end closing; and the provision of a carton in which a minimum amount of material is employed so that a low carton unit cost is maintained.

.These and other objects will become apparent from the following description in which reference is directed .to the accompanying drawings.

FIG. 1 is a plan view on a reduced scale of a blank from which the subject carton is erectable;

FIG. 2 is an isometric view of the subject carton partially erected with opposite ends thereof open for product filling;

FIG. 3 is a partial isometric view of the carton with one end thereof partially closed;

FIG. 4 is a partial isometric view of the carton showing an end thereof substantially closed and illustrating the function of the shoulder means on one closure flap;

FIG. 5 is a partial isometric View of the carton with an end thereof completely closed;

FIG. 6 is a partial isometric view of a carton construction which embodies material saving revisions over heretofore known conventional cartons; such figure illustrates the type of interference which has been encountered between the major closure flaps employed at an end of such a revised material saving carton during closing thereof;

FIG. 7 is a plan view of the subject carton, on a reduced scale, in collapsed state for shipment and storage.

Before describing the subject carton in detaiLreference will be directed briefly to a prior art conventional carton of which the subject car-ton and also the revised carton shown in FIG. 6 are specific improvements. Previously available conventional end loading cartons generally employ a series of cooperable major and minor end closure flaps at a carton end which are folded inwardly and which are maintained folded by interengaging tab and slit means provided on cooperable major closure flaps. Generally, however, in such conventional rectangular cartons .at least one of such cooperable major closure flaps is of large size designed to completely cover 'and close the end opening of the carton. Thatis, such major flap is sufficiently large to extend the full distance between the carton wall to which it is hingedly connected and the opposite parallel carton wall when the flap is folded to close the carton end.

It has been found, however, that the large major fllalp construction employed in conventional cartons is unnecessary and results in more material being employed in each carton thanis required. As a result, the unit carton cost is increased without increasing carton efficiency or etfectiveness. Accordingly, in efforts to reduce carton unit cost, a modified or revised carton construction was devised in which one or both major end closure flaps are cut off or shortened so that the same do not extend the full distance between opposite carton walls when the carton .end is closed so that a savings of material is effected.

The revised carton which was devised to effect material savings at opposite carton ends is shown in FIG. 6.

However, when such revised cartons having one or both major end flaps shortened are set up and closed on automatic machinery, it has been found that quite frequently the major closure flaps to be interengaged interfere with each other during folding, in the manner sho wn .in FIG. 6, as will be described in greater detail hereinafiter.

Accordingly, difiiculty frequently isencountcred in filling and closing such revised cartons on automatic machinery. As a result, although paperboard material is saved in each such carton, other undesirable factors frequently are encountered which had not previously been encountered with conventional cartons embodying lange size, unshortened major closure flaps.

The subject carton was devised as a further improved revision of the aforementioned revised carton. The subjcct carton effects not onlya highly desirable savings of material, but also precludes the aforementioned interference between the major end closure-flaps as the carton end is closed. That is, the subject carton includes closure flaps at a carton end is provided with camming shoulder means of the type to be described which effectively prevent any such interference so that the subject carton may be rapidly and readily filled and closed on high speed carton machinery. Furthermore, because the subject camming shoulders are provided from what normally would he waste material, no increased unit carton cost "results therefrom.

Referring first to FIG. 1, the subject carton 1 in blank form comprises a series of rectangular body panels 2, 3, 4 and 6 hingedly connected with each other along spaced, generally parallel fold lines L. Desirablly alternate body panels 2 and 4 are of less width than alternate body panels 3 and 6 so that the resulting carton body when erected is provided with a substantially rectangular crosssection. The particular dimensional relationship between the widths of the respective body panels is not critical and may be varied to meet a particular need, but preferably panels 2 and 4 are of the same width while panels 3 and 6 are of the same width so that a neat rectangular carton body is provided. Hereinafter reference will be directed to panels 2 and 4 as being the minor body panels because of their reduced width, while panels 3 and 6 will he referred to as the major body panels because of their increased width.

As noted in FIG. 1, preferably each of the major and minor body panels is of essentially the same length with each opposite end margin of each of the respective panels being defined by one of a series of substantially co-linear fold lines T which extend transversely to the series of fold lines 'L mentioned previously. That is, fold lines T define the opposite end margins of the respective body panels.

For a well known purpose, a securing flap 7 is hingedly connected to one of the body panels along one fold line L. In the embodiment illustrated such securing flap is connected to major .body panel 6. Such flap is to be coated with a suitable adhesive and is to be secured to the inner surface of minor body panel 2 when the carton is erected, as best seen in FIG. 2, in the well known manner.

As illustrated in FIG. 2, when securing flap 7 is secured to body panel 2, a continuous rectangular carton body is defined by the body panels with major panels 3 and 6 extending opposite and parallel to each other and with minor panels 2 land 4 similarly extending opposite and parallel to each other.

Means for closing a carton after product been inserted therein is provided at-each end of the carton. Preferably such means is the same at each carton end as has been illustrated in FIGS. 1 and 2. However, it should be understood that the novel closure means disclosed need not be employed at both carton ends unless so desired.

Hereinafter reference will be directed only to the closure means at one end of the carton because preferably both closure means are identical. Similar reference numerals primed are employed for the closure means at the carton end opposite from the end described.

Such closure means comprises a series of closure flaps with each flap of the series being hingedly connected to a given carton body panel along a fold line T. Such flap series, as seen in FIG. 1, comprises a pair of alternate minor closure flaps 8 and 9 and an alternate pair of major closure flaps .11 and 12. As seen in the drawings, the

minor closure flaps are hingedly connected to the respective minor'bcdy panels and the major closure flaps are connected to the respective major body panels so that the minor flaps are opposite each other when the carton is erected, as are the major flaps. As noted in the blank configuration of the carton seen in FIG. 1, preferably each of the respective closure flaps is substantially coextensive with the width of its associated body panel.

The minor closure iiaps desirably are of generally rectangular configuration, while the major closure flaps the major body panels 3 and 6 when the carton is erected and the carton end is closed. That is, the length of the respective major closure flaps is less than the Width of the respective minor body panels which defines the thick ness of the carton when erected. Referring to FIG. 1, it is seen that distance D (that is, the length of each major flap between its line of hinged connection '1 to its associated major body panel and its outer marginal extremity) is less than distance D (which is the Width of the respective minor body panels). As a result, the aforementioned highly desirable conservation of material is effected with the subject car-ton in that each of the major flaps is designed to be just sufficiently long enough to permit secure interengagcment thereof in the manner to be described without requiring unnecessary material. That is, the major flaps cooperate in completelyclosing the carton end but each major flap individually is of insufficient lengthto close the end. Note FIG. 5.

Because the minor closure flaps 8 and '9 are employed generally to insure closing at the corners of the carton end, such flaps need be no longer'than the major closure flaps 1 1 land 12. As a result, the outer marginal extremities 8a, Ma, 9111 and 12a of the respective minor and major closure flaps are substantially co-linear as defined by a straight line 13 passing therethrou'gh, as seen in FIG. 1.

Referring to FIGS. 2, 3 and 4, it should be understood that a carton end is closed by folding the opposite minor flaps 8 and 9 inwardly towards each other, and thereafter folding the opposite major flaps 1'1 and 12 inwardly toward each other to overlie the folded minor flaps. The

major flaps are folded into over-lapping relationship with.

slit 16 in major flap 1'1 and a locking tab 17 on major flap 12. Slit 16 is positioned inwardly from the marginal extremity 11a of flap 11, and tab 17 does not extend beyond the marginal extremity 12a of flap 12. That is,

tab 17 lies entirely within the marginal confines of fiap' 12. Tab 17 is lockingly receivable in slit 16 to maintain the car-ton end closed as seen in FIG. 5. When in this condition, with both ends closed, the carton preferably is overwrapped in the well known manner on conventional.

overwrapping apparatus. To impart flexibility to the flap 11 in the'vicinity of slit 16, a pair of small slits 16a are provided which communicate with slit 16 and permit the flap to be deformed in the vicinity of the slit during tab insertion without attendant flap damage. i

Tab 17 is bendably connected to its associated major closure flap 12 along a line of connection which is a continuation of an inner marginal edge portion 20 of the flap. Such edge portion also defines short cuts 21 which separate opposite ends of the locking tab from the p slit interengagement is not such that the canton is. un-' duly difficult to open so that the product may be readily removed by the ultimate consumer.

An important feature of the subject invention includes the provision of a pair of oamming shoulder portions 22 and 23 on major flap 12 which are cooperable he slit 16 is located in major flap 11 so that inner with the opposite major flap '11 to preclude interference between such major flaps when the carton end is closed. Such shoulders project from the inner marginal edge 20 of flap 12 on opposite sides of the locking tab and are defined by cut out portions 24 and 26 of general-1y triangular configuration which delineate opposite ends of the locking tab.

In the heretofore mentioned revised cartons the flap corner portions which define the shoulders generally are discarded as waste. That is, in such revised cartons the major flap 12 is normally cut away at its corners so that inner marginal edge 20 extends straight to the lateral edges of the flap from each side of the locking tab as seen in FIG. 6. As a result, the incorporation of camming shoulders in the subject carton does not in any Way add to the unit cost of the car-ton because such shoulders are defined by what would be waste material. The cross hatched areas seen in FIG. 1, shown for purposes of illustration, define the corner shoulder portions of this invention which would normally be discarded as Waste in the aforementioned revised cartons.

The cammi-ng shoulders 22 and 23 perform the important function mentioned previous-1y of positively precluding interference between the major closure flaps when the subject carton end is closed. That is, as the locking tab is bent into the locking slit, the oamrning shoulders, as seen in FIG. 4, preclude any interference or interengagement between the marginal extremities 11a and 12a of the respective major flaps by providing flat surfaces over which the marginal extremity 11a of major flap 11 can slide as the major flaps are folded toward each other. In this regard, the locking tab is separate from the shoulders and is bendable into the locking slit independently of the shoulders.

Because cartons intended for packaging foods and other products, as noted previously, preferably are closed on automatic machines which use flap deflecting plow devices or fingers in a well known manner, and because such closing operations are carried out at high speeds, any such flap interference cannot be tolerated because it results in carton damage and/or machine operation disruption. Additionally, even if the subject carton is closed by hand, :the closing operation is greatly facilitated due to the camming shoulders.

By way of example and illustration, reference is directed to FIG. 6 which illustrates a revised material saving carton which does not employ the subject camming shoulders. As seen in such figure the marginal extremities of the major flaps of such revised cartons can and frequently do become interengaged during the flap folding operation. This precludes proper engagement of the locking tabin the slit. That is, it has been found that upon folding of opposite major closure flaps 111 and 112 to insert the locking tab 117 into locking slit 116, the marginal extremities 111a and 112a of the major flaps of the revised carton frequently become interlocked in the manner seen in FIG. 6.

The major flaps of the revised carton have been found frequently to interfere with each other, particularly during high speed closing operations on automatic machinery. As a result, proper end closing and tab and slit interengagement frequently was frustrated and carton damage resulted.

With the subject construction employing the subject camming shoulders, all such flap interference is positively precluded in that the marginal extremities of the major flaps are precluded from contacting each other by the aforementioned camming shoulders. As a result, the subject carton may readily be set up, filled and closed upon high speed carton machinery without difliculty. Furthermore, because such camming shoulders would be discarded as waste material in the revised carton-s described and shown in FIG. 6, the unit cost of the subject carton is in no Way increased.

A further important feature provided by the camming shoulder portions is illustrated by FIG. 5 in that such shoulders, after the carton end has been closed, provide enlarged surfaces by means of which the consumer may grasp the major carton flap 12 between thumb and forefinger along the shoulder lateral edges to readily disengage the carton locking tab from the locking slit. This permits ease of carton opening which otherwise would be more difiicu lt in the absence of such shoulders.

As seen in FIG. 7, preferably the subject carton is collapsed for shipment and storage. In such condition, the canton ends are open and one major body panel and .one minor body panel with their attached closure flaps define each side of the collapsed carton. To erect the carton for filling, it is merely necessary to exert inward pressure on opposite side edges of the collapsed carton in the well known manner.

By Way of example and in no way intending to limit the subject invention, one specific example of a paperboard carton well suited for packaging frozen foods, such as frozen vegetables, will {be described. In such carton the width of the major body panels 3 and 6 is four inches and the length thereof is five and one-quarter inches. The width of the minor body panels 2 and 4 is one and one-half inches. The width of adhesive flap 7 is approximately five-eighths inch with the length thereof corresponding substantially to the length of the respective body panels.

As mentioned previously, the width of the respective major and minor closure flaps at the hinged connection thereof to their respective body panels is substantially equal to the width of such body panels so that the major flaps are each four inches wide and the minor flaps are one and one-half inches wide. Preferably the overall lengths of all the closure flaps are substantially equal, and in this specific embodiment each closure flap is approximately one and one-eighth inch long measured from its marginal extremity to its hinged connection with its associated body panel. This closure flap length results in a savings of three-eighths of an inch of material in each of the major closure flaps.

When a canton having the aforementioned exemplary dimensions is erected and its opposite ends closed, the resulting carton is five and one-quarter inches long by four inches wide by one and one-half inches thick.

Having thus made a full disclosure of this invention, reference is directed to the appended claims.

I claim:

1. A material-saving flattened collapsed tubular carton having opposite ends both of which are open and unrestricted when said carton is in the flattened collapsed state, said carton being adapted to retain a product therein when the same is erected from said flattened collapsed state and the opposite ends thereof are closed; said carton comprising a pair of major body panels and a pair of minor body panels hingedly connected to define a generally rectangular carton body when said carton is erected, said carton in the flattened collapsed state having one major panel and one minor panel on each side of the flattened carton, and end closure means at both of said opposite ends of said carton for closing said ends when said carton is erected, said closure means at at least one of said opposite carton ends being designed to conserve carton material at such carton end, said collapsed carton being erectable from said flattened collapsed state into an open ended tubular carton and said end closure means thereon being closable on high speed automatic machinery; said closure means at such one carton end comprising a pair of minor closure flaps hingedly connected to end margins of said minor body panels, and a pair of major closure flaps hingedly connected to end margins of said major bod-y panels, said major and minor closure flaps being of a width no greater than the width of their associated body panels,

each of said major flaps being of a length which is substantially less than the width of said minor body panels so :that said major flaps do not extend the full distance across the carton end when folded whereby a savings in carton material is effected, said minor closure flaps being of a length no greater than the longer of said major closure flaps, said minor flaps being foldable inwardly towards each other in a first direction and said major flaps being foldable inwardly over said minor flaps towards each other in a direction generaily transverse 'to said first direction when said carton is erected to close such carton end, said major flaps terminating short of the major body panels opposite thereto and being interengageable when thus folded, one of said major flaps having a locking slit therein spaced inwardly from an outer marginal extremity thereof, said one major flap otherwise being generally imperforate, the other major flap having a locking tab there-on adapted to be received in said slit, said other major flap having a cut out portion on each side of said tab extending into such flap from an outer marginal extremity thereof, said out out portions defining a pair of camming shoulders on opposite sides of said tab which are engageable with said one major flap when said major flaps are folded towards each other to preclude interference between such flaps as said tab is being inserted into said slit, said camming shoulders defining flap corner portions which are free of other locking tabs whereby said shoulders are free of interlocked engagement with said one major flap when said carton is erected and said one end thereof is closed. I

2. The collapsed canton of claim 1 in which said locking tab on said other major closure fiap terminates within the marginal confines of said carton as defined by the outer marginal extremities of said major closure flaps.

References Cited inthe file of this patent UNITED STATES PATENTS 

1. A MATERIAL-SAVING FLATTENED COLLAPSED TUBULAR CARTON HAVING OPPOSITE ENDS BOTH OF WHICH ARE OPEN AND UNRESTRICTED WHEN SAID CARTON IS IN THE FLATTENED COLLAPSED STATE, SAID CARTON BEING ADAPTED TO RETAIN A PRODUCT THEREIN WHEN THE SAME IS ERECTED FROM SAID FLATTENED COLLAPSED STATE AND THE OPPOSITE ENDS THEREOF ARE CLOSED; SAID CARTON COMPRISING A PAIR OF MAJOR BODY PANELS AND A PAIR OF MINOR BODY PANELS HINGEDLY CONNECTED TO DEFINE A GENERALLY RECTANGULAR CARTON BODY WHEN SAID CARTON IS ERECTED, SAID CARTON IN THE FLATTENED COLLAPSED STATE HAVING ONE MAJOR PANEL AND ONE MINOR PANEL ON AT BOTH OF SAID OPPOSITE ENDS OF SAID CARTON FOR CLOSING SAID ENDS WHEN SAID CARTON IS ERECTED, SAID CLOSURE MEANS EACH SIDE OF THE FLATTENED CARTON, AND END CLOSURE MEANS AT AT LEAST ONE OF SAID OPPOSITE CARTON ENDS BEING DESIGNED TO CONSERVE CARTON MATERIAL AT SUCH CARTON END, SAID COLLAPSED CARTON BEING ERECTABLE FROM SAID FLATTENED COLLAPSED STATE INTO AN OPEN ENDED TUBULAR CARTON AND SAID END CLOSURE MEANS THEREON BEING CLOSABLE ON HIGH SPEED AUTOMATIC MACHINERY; SAID CLOSURE MEANS AT SUCH ONE CARTON END COMPRISING A PAIR OF MINOR CLOSURE FLAPS HINGEDLY CONNECTED TO END MARGINS OF SAID MINOR BODY PANELS, AND A PAIR OF MAJOR CLOSURE FLAPS HINGEDLY CONNECTED TO END MARGINS OF SAID MAJOR BODY PANELS, SAID MAJOR AND MINOR CLOSURE FLAPS BEING OF A WIDTH NO GREATER THAN THE WIDTH OF THEIR ASSOCIATED BODY PANELS, EACH OF SAID MAJOR FLAPS BEING OF A LENGTH WHICH IS SUBSTANTIALLY LESS THAN THE WIDTH OF SAID MINOR BODY PANELS SO THAT SAID MAJOR FLAPS DO NOT EXTEND THE FULL DISTANCE ACROSS THE CARTON END WHEN FOLDED WHEREBY A SAVINGS IN CARTON MATERIAL IS EFFECTED, SAID MINOR CLOSURE FLAPS BEING OF A LENGTH NO GREATER THAN THE LONGER OF SAID MAJOR CLOSURE FLAPS, SAID MINOR FLAPS BEING FOLDABLE INWARDLY TOWARDS EACH OTHER IN A FIRST DIRECTION AND SAID MAJOR FLAPS BEING FOLDABLE INWARDLY OVER SAID MINOR FLAPS TOWARDS EACH OTHER IN A DIRECTION GENERALLY TRANSVERSE TO SAID FIRST DIRECTION WHEN SAID CARTON IS ERECTED TO CLOSE SUCH CARTON END, SAID MAJOR FLAPS TERMINATING SHORT OF THE MAJOR BODY PANELS OPPOSITE THERETO AND BEING INTERENGAGEABLE WHEN THUS FOLDED, ONE OF SAID MAJOR FLAPS HAVING A LOCKING SLIT THEREIN SPACED INWARDLY FROM AN OUTER MARGINAL EXTREMITY THEREOF, SAID ONE MAJOR FLAP OTHERWISE BEING GENERALLY IMPERFORATE, THE OTHER MAJOR FLAP HAVING A LOCKING TAB THEREON ADAPTED TO BE RECEIVED IN SAID SLIT, SAID OTHER MAJOR FLAP HAVING A CUT OUT PORTION ON EACH SIDE OF SAID TAB EXTENDING INTO SUCH FLAP FROM AN OUTER MARGINAL EXTREMITY THEREOF, SAID CUT OUT PORTIONS DEFINING A PAIR OF CAMMING SHOULDERS ON OPPOSITE SIDES OF SAID TAB WHICH ARE ENGAGEABLE WITH SAID ONE MAJOR FLAP WHEN SAID MAJOR FLAPS ARE FOLDED TOWARDS EACH OTHER TO PRECLUDE INTERFERENCE BETWEEN SUCH FLAPS AS SAID TAB IS BEING INSERTED INTO SAID SLIT, SAID CAMMING SHOULDERS DEFINING FLAP CORNER PORTIONS WHICH ARE FREE OF OTHER LOCKING TABS WHEREBY SAID SHOULDERS ARE FREE OF INTERLOCKED ENGAGEMENT WITH SAID ONE MAJOR FLAP WHEN SAID CARTON IS ERECTED AND SAID ONE END THEREOF IS CLOSED. 